Clopidogrel loading doses and outcomes of patients undergoing percutaneous coronary intervention for acute coronary syndromes.

BACKGROUND

In clinical practice, the use of clopidogrel loading doses higher than the standard 300 mg dose is becoming more common in percutaneous coronary intervention (PCI) despite a paucity of clinical evidence to support such a strategy.

OBJECTIVE

This study sought to assess whether patients with acute coronary syndromes (ACS) undergoing PCI would receive additional benefit from higher-than-standard (300 mg) loading doses of clopidogrel.

METHODS

We performed a retrospective analysis of outcomes in 2,484 patients with ACS undergoing PCI who received either standard dose (300 mg, n = 1,199) or high-dose (> 300 mg, n = 1,285) clopidogrel loading at 1 of 14 study hospitals between January 2003 and September 2004.

RESULTS

At 60 days after discharge, the rate of the combined endpoint of myocardial infarction (MI), stroke, coronary revascularization or death was higher in the high-dose group (37.1< vs. 20.5%; p < 0.0001), primarily because of a higher rate of MI in the high-dose group (34.7% vs. 17.3%; p < 0.0001). Bleeding event rates did not differ between the high-dose and standard-dose groups. Propensity scoring was used to compare event frequencies between patients with similar clinical risk, and this analysis also showed no additional clinical benefit associated with higher clopidogrel loading doses.

CONCLUSION

Based on this retrospective study, the use of higher (> 300 mg) clopidogrel loading doses is not associated with additional clinical benefit in patients with ACS undergoing PCI in clinical practice.